81424263 has 8 divisors (see below), whose sum is σ = 108645376. Its totient is φ = 54243000.

The previous prime is 81424249. The next prime is 81424283. The reversal of 81424263 is 36242418.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 81424263 - 2⁴ = 81424247 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81424263.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81424223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4813 + ... + 13638.

It is an arithmetic number, because the mean of its divisors is an integer number (13580672).

Almost surely, 2^81424263 is an apocalyptic number.

81424263 is a deficient number, since it is larger than the sum of its proper divisors (27221113).

81424263 is a wasteful number, since it uses less digits than its factorization.

81424263 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19925.

The product of its digits is 9216, while the sum is 30.

The square root of 81424263 is about 9023.5393831911. The cubic root of 81424263 is about 433.4289796104.

The spelling of 81424263 in words is "eighty-one million, four hundred twenty-four thousand, two hundred sixty-three".